Direct current visual evoked potentials on light and dark adaptation process.

采用直流电放大法记录枕叶视觉诱发电位（VEP），探讨短时亮暗适应过程。刺激模式为持续时间为10、50、100、500、1000ms的亮、暗阶跃函数和5、10、20Hz的亮、暗闪光串。从50个原始数据计算平均DC VEP和AC VEP（时间常数0.3s）。DC VEP在暗刺激和亮刺激下均出现相应的适应性变化：暗适应时DC VEP正移（正），亮适应时DC VEP负移（正）。有自适应因子的训练VEP仿真结果比无自适应因子的训练VEP仿真结果拟合得更好。建立了一个包含起始、偏移、自适应、对比度和延迟因子的VEP模型。介绍了几种用于实验的计算机程序EASY（EEG Analysis System）。

Visual evoked potentials(VEP) were recorded by direct current amplification from Occipital to investigate the short term light and dark adaptation process. Stimulus patterns were light and dark step functions with the duration of 10, 50, 100, 500, 1000ms, and light and dark flash trains with 5, 10 and 20Hz. Averaged DC VEP and AC VEP(time constant 0.3s) were computed from 50 raw data. Adaptational shifts of DC VEP were found corresponding to light and dark stimulations: upward shift(negative) was for light adaptation and downward shift(positive) was for dark adaptation. Simulation of train VEP with adaptation factor was fitted better than without adaptation factor. A VEP model was proposed including onset, offset, adaptation, contrast and delay factors. Some of computer programs for experiment, EASY(EEG Analysis SYstem), were introduced to researchers of experimental psychology.